UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C.  20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

AMENDMENT NO.3

Southwest Royalties Institutional Income Fund X-C, L.P.

(Name of Issuer)

Limited Partnership Interests

(Title of Class of Securities)

Not Applicable

(CUSIP Number)

L. Paul Latham

Southwest Royalties, Inc.

6 Desta Drive, Suite 6500

Midland, Texas 79705-5510

(432) 682-6324

(Name, Address and Telephone Number of Person

Authorized to Receive Notices and Communications)

February 25, 2008

(Date of Event which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box:  □

CUSIP No. Not Applicable

(1)	Names of Reporting Persons	Southwest Royalties, Inc.
(2)	Check the Appropriate Box	(a)
	if a Member of a Group	(b)  x
(3)	SEC Use Only
(4)	Source of Funds	WC
(5)	Check if Disclosure of Legal
	Proceedings is Required
	Pursuant to Items 2(d) or 2(e)	Not Applicable
(6)	Citizenship or Place of
	Organization	Delaware corporation
Number of Shares/Units Beneficially Owned by Each Reporting Person With:
(7)	Sole Voting Power	480.6 Units
(8)	Share Voting Power	None
(9)	Sole Dispositive Power	480.6 Units
(10)	Shared Dispositive Power	None
(11)	Aggregate Amount Beneficially
	Owned by Each Reporting Person	480.6 Units
(12)	Check if the Aggregate Amount
	in Row (11) Excludes Certain Shares	Not Applicable
(13)	Percent of Class Represented
	by Amount in Row (11)	8% of class of 5,983 Units
(14)	Type of Reporting Person	CO (Managing General Partner of Issuer)

Item 1.	Type of Security:	Limited Partnership Interests ("Units")
	Name of Issuer:	Southwest Royalties Institutional Income Fund X-C, L.P.
	Address of Issuer's	6 Desta Drive
	Principal Executive	Suite 6500
	Offices:	Midland, Texas 79705-5510
Item 2(a).	Name of Person Filing:	Southwest Royalties, Inc.
Item 2(b).	Address of Principal	6 Desta Drive, Suite 6500
	Business Office:	Midland, Texas 79705-5510
Item 2(c).	Present Occupation:	Not Applicable
Item 2(d).	Criminal Convictions:	None
Item 2(e).	Civil Securities Laws
	Injunctions or Prohibitions:	None
Item 2(f).	Citizenship:	Delaware, U.S.A.
Item 3.	Source of Funds:	Working capital of the Reporting Person.
Item 4.	Purpose of Transactions:
	The Reporting Person satisfied the requirements of the Right of Presentment contained in the Issuer's Agreement of Limited Partnership whereby the Reporting Person, as Managing General Partner, agrees to acquire Units from limited partners seeking an exit from the Issuer at a formula price.

Item 5.	Interest in Securities
	The Reporting Person, which is the Issuer: Managing General Partner of the Issuer, holds a total of 480.6 Units of limited partnership interests over which it has sole voting and dispositive powers.  These Units represent 8.0% of the total 5,983 Units, which are issued and outstanding.  The purchase transactions which resulted in the ownership of the Reporting Person increasing from 7.7% to 8.0% occurred between July 1, 2007 and February 25, 2008 when the Reporting Person purchased an additional 22.5 Units as part of the Issuer's Right of Presentment program.  The price per unit ranged from $48.83 to $77.00.
Item 6.	Contracts, Arrangements,
	Undertakings or Relationships
	with Respect to Securities of the Issuer:	Not Applicable
Item 7.	Material to Be Filed as Exhibits:	Not Applicable

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Date: February  27, 2008	By:	/s/ L. Paul Latham
		L. Paul Latham, President and
		Chief Executive Officer,
		of Southwest Royalties, Inc.
		the Managing General Partner